1. Field of the Invention
This invention relates to a device for withdrawing blood or other fluids from a patient employing a dual-tip needle element, and particularly relates a device where one of the needle tips is provided with a guard that prevents accidental needle sticks.
2. Background Discussion
It is a common practice in withdrawing from a patient blood samples, or other body fluids, to employ a device which includes a disposable dual-tip needle element. This needle element is removably connected to a reusable tube holder which holds a sealed tube having a partial vacuum in the interior of the tube. Becton Dickinson corporation makes such a sampling device under the brand name of Vacutainer.
The disposable needle element is initially housed within a container that allows the nurse to connect the needle element to the tube holder without directly touching the needle element. This container usually includes a removable cover which surrounds the end (the patient end) of the needle element that will eventually be stuck into the patient's body. The nurse, however, does not remove the cover until she is ready to withdraw blood from the patient, whereupon the patient end of the needle is inserted into the into the patient's body. The other end (the tube end) of the needle element is covered by a cap member which is removed prior to connecting assembly to the tube holder.
With the needle inserted in the patient, the tube is pushed into the tube holder, with the sealed end of the tube being directed towards the tube end of the needle element. As the nurse advances the tube towards the tube end of the needle element, the side walls of the tube holder guide the tube. When the sealed end reaches the tube end of the needle, the needle pierces the sealed end, with the tip of the needle extending into the interior of the tube. The vacuum within the tube causes blood to flow immediately from the patient through the needle element into the interior of the tube, filling it.
Although this device is extremely useful there is one serious problem associated with using it. Namely, accidental needle sticks. Upon removal of the needle from the patient, and in the process of disconnecting the needle element from the tube holder, the nurse recovers the exposed patient end of the needle. When this is done, there is the possibility that an accidental needle stick will occur. When this happens, the nurse is required to undergo a blood test to determine if she is already carrying an infectious disease. If she is not and later becomes infected, the hospital employing the nurse will be legally liable.